I used to work a large investment bank, and it was not uncommon for our clients and auditors to ask about how we handled, security, financial transactions etc.

I used to work a large investment bank, and it was not uncommon for our clients and auditors to ask about how we handled, security, financial transactions etc. Our rules were pretty much as follows. 1. Everyone involved signs an NDA. 2. No property of the bank is allowed to leave the premises at any point in time. Any supporting documentation was printed out and they were allowed to review it in certain designated rooms. The documents were not allowed to leave that room and they were reviewed to make sure nothing was missing at the end. 3. Any questions must be provided in writing so there is a record of the question and response.